1. Field of the Invention
The present invention relates generally to seats for motor vehicles and, more specifically, to a programmable seat back damper assembly for a seat in a motor vehicle.
2. Description of the Related Art
It is known to provide seats for motor vehicles such as an automotive vehicle. Typically, a seat includes a generally horizontal seat cushion portion and a generally vertical seat back portion operatively connected to the seat cushion portion. The seat may include at least one, preferably a pair of tracks to allow longitudinal adjustment of the seat cushion portion. The seat may include a recliner for reclining the seat back portion relative to the seat cushion portion by an occupant in the seat.
It is known to provide an energy absorber or damper for a seat back portion of a seat in a motor vehicle. An example of such a damper is disclosed in U.S. Pat. No. 5,722,722. In this patent, a damper and recliner are connected in a substantially parallel relationship with respect to each other and secured to the seat back portion and seat track. The recliner is configured to be disengageable in a high-energy impact, thereby allowing the damper to dissipate energy as the seat back portion pivots with respect to the seat track.
One disadvantage of the above damper is that it is not programmable to provide damping characteristics based on impact event characteristics. Another disadvantage is that the above damper does not allow limited rotation of the seat back portion. A further disadvantage is that the above damper and release mechanism includes a squib release mechanism, which is an explosive device that is not resettable for multiple uses.
Accordingly, the present invention is a programmable seat back damper assembly for a seat in a motor vehicle including a generally horizontal seat cushion portion operatively connected to vehicle structure and a generally upright seat back portion operatively connected to the seat cushion portion. The programmable seat back damper assembly includes a recliner for operative connection to the seat back portion and the seat cushion portion. The programmable seat back damper assembly also includes a damper for operative connection to the seat back portion and the seat cushion portion and having a magneto-rheological (MR) fluid therein. The programmable seat back damper assembly further includes a controller electrically connected to the damper to control an apparent viscosity of the MR fluid to increase and decrease damping of the damper for adjusting an angle of the seat back portion relative to the seat cushion portion.
One advantage of the present invention is that an improved programmable seat back damper assembly is provided for a seat in a motor vehicle. Another advantage of the present invention is that the programmable seat back damper assembly uses a magneto-rheological fluid damper to dissipate energy for a seat back of a vehicle seat. Yet another advantage of the present invention is that the programmable seat back damper assembly reduces occupant kinetic energy during an impact on the vehicle through programmed and limited seat back rotation. Still another advantage of the present invention is that the programmable seat back damper assembly can be programmed to provide a dampening profile based on impact event characteristics. A further advantage of the present invention is that the programmable seat back damper is resettable and useable.
Other features and advantages of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description when taken in conjunction with the accompanying drawings.